POS0014 EFFICACY AND SAFETY OF JAK INHIBITORS IN REFRACTORY OR INITIAL TREATMENT OF ADULT ONSET STILL’S DISEASE
Authors: Z. Chen, J. Tan, T. Cheng, X. Wu, J. Gu, Z. Liao
Journal: Annals of the Rheumatic Diseases (2022)

Background Inappropriate activation of pro-inflammatory cytokines such as interleukin (IL)-1, IL-6 or IL-18, is a pathogenic cornerstone in adult onset Still’s disease (AOSD). Beyond therapies targeting IL-1 and IL-6, Janus kinases (JAK) inhibitors have been suggested to be efficient in refractory AOSD patients [1]. Objectives To assess the efficacy and safety of JAK inhibitors in the treatment of AOSD patient refractory to, or with initial treatment. Methods This retrospective study was based on our single center of the department of rheumatology and immunology. The data was collected from the patients’ medical records using a standardized questionnaire and analyzed at different time points. The response to JAK inhibitors was categorized as complete remission (CR), partial remission (PR) or failure (F) [2]. Results 7 patients were recruited (Table 1), including 4 refractory patients and 3 initial patients. Mean age at JAK inhibitor treatment start was 27.5 years for refractory patients and 35 years for initial patients; and mean disease duration was 66.5 months and 1 month respectively. All patients had fever and polyarthritis, 5 patents had rash. In addition, pulmonary hypertension, abnormal liver function tests, abdominal pain, and heart failure were also observed in our patients. Response to corticosteroids, conventional synthetic or biological Disease Modifying Anti-Rheumatic Drugs (DMARDs) had been considered inadequate in 4 refractory patients. Tofacitinib was added in the initial treatment for 3 patients for high disease activity. In total, baricitinib was used in 2 patients and tofacitinib in 5 patients. Steroids were concurrently used in 6 patients, MTX in three, SASP and NSAIDs in one. At a mean follow up of 3.8 months, complete remission was observed in one patient (with tofacitinib), partial remission was in 5 patients (4 patients with tofacitinib and one with baricitinib), and failure in one (patients with baricitinib). At the last visit, steroids could be decreased but not stopped in those 6 patients. Tolerance of JAK inhibitors was excellent, none infectious disease or other severe side effect were observed. Table 1. Characteristics of the AOSD patients No. Sex Age (year) Disease Duration (Month) Main symptoms Treatments before JAKionset JAKi Steroids at onset Conconmitant treatment Steroids at the end of F-U F-U(month) Outcome 1 M 26 29 Fever, polyarthritis Pred+MTX Tofacitinib 0 MTX 0 4 PR 2 M 25 9 Fever, polyarthritis, rash, pulmonary hypertension Pred+MTX Baricitinib 16 MTX+Pred 12 4 F 3 M 38 12 Fever, polyarthritis, rash Pred+MTX+CsA+NSAIDs Tofacitinib 24 Pred 12 3 PR 4 M 21 216 Fever, polyarthritis Pred+MTX+SASP+NSAIDs+TNFi Baricitinib 4 Pred+MTX+SASP+NSAIDs 4 3 PR 5 F 33 1 Fever, polyarthritis, rash, abnormal liver function tests Pred Tofacitinib 40 Pred 2 5 CR 6 F 47 1 Fever, polyarthritis, rash, abdominal pain Pred Tofacitinib 36 Pred 4 5 PR 7 F 25 1 Fever, polyarthritis, rash, heart failure Pred Tofacitinib 40 Pred 12 3 PR Pred: prednisone; MTX: Methotrexate; SASP: salicylazosulfapyridine; CsA: ciclosporin A; NSAIDs: Non-Steroidal Antiinflammatory Drugs; TNFi: Tumor necrosis factor inhibitor. CR: complete remission; PR: partial remission; F: failure. Conclusion JAK inhibitors treatment may be helpful for some patients with refractory AOSD, or patients with severe disease activity at initial treatment. Different treatment responses were observed in these short series of cases, which might be due to the phenotype of patients. However, the scale of patients in our study was too low to draw a conclusion. Further study and additional information are needed to evaluate more precisely the risk-benefit ratio of this treatment, and a possible difference in efficacy among the different groups of patients or JAK inhibitors. References [1]Aosd T, Table E. Ann Rheum Dis 2020; 79 :842–4. [2]Vercruysse F, Barnetche T, Lazaro E, et al. Arthritis Res Ther 2019; 21 :1–11. doi:10.1186/s13075-019-1838-6. Figure 1. Changes in laboratory test (A) WBC; (B) CRP; (C) ESR;(D) Ferritin. M0: baseline; M1: month 1; M3: month 3; M5: month 5. Acknowledgements None Disclosure of Interests None declared